10W40 vs 0W40

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12,150
Location
Colorado Springs
Thanks for the information! Interesting to read the opposite view.
According to some owners here in the US, Redline 5W50 showed up as really good alternative to 10W60. Redline 5W50 could have HTHS very close to TWS 10W60.
As for rod bearings on N55 first issue is known fact: people do not prime oil pump after OFHG change.
Second is that there are suddenly numerous N55 engines with rod bearings failure. But why now? I mean engine is in use since 2010. I think it is since they moved to that LL01FE garbage.
 
Messages
5,379
Location
down in the park
In the german oil club Forum, 0w-40 is regarded as a very bad choice, because it is just a marketing gag. Poor quality oil, boosted with VI Improvers that shear down in no time. Avoid it all cost.
If you want to protect your engine, you need a thick base oil, therefore 10w-40. As a side note, allways remember, cold start wear dont exist.
All you need is a thick base oil, thats the most important thing.
;)

I wonder when all the manufacturers that recomemnds 0w-40 for their high end sports cars wake up and see that they do it wrong...
;)

Compared to a full synthetic 5W40, it could be true that the base oil viscosity of the 0W40 is less and boosted with more VII. But if you buy any off the shelf 5W40, the oil will have a majority or all grp III base oil, whereas a 0W40 will at least in part be PAO. 10W40 off the shelf will be a blend of grp I and group III oils in europe and will most likely have more VII than either 5W40 or 0W40.

But the premise of preferring thicker base oil has merit. I chose my oil over the advised 5W30 C2 for the extra protection. It also has about 10% more phosphorous and calcium than any low saps oil which also makes me sleep better at night
 
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5,379
Location
down in the park
Yes, but honestly, thats what the "Bosses" tell people in the german Oil club forum, no kidding!

I just want to share it, trying to maybe make some BITOG members smile. I dont want to de-rail this thread, i dont want to confuse people...
Sorry if my posting went wrong.


But, seriously:
There are reports in german forums, from people that seem thrustworthy, that engines who have a reputaion for problems with rod Bearings (BMW) benefit from 10w- oils. There are still a few high quality 10w-40 around.

All others, just use a 0w-40 with Porsche A40 / MB 229.5 specification and you are fine.

There's a possibility those 10W40 are on the thicker end of the sae j300 scale, and have a higher HTHS viscosity. Total quartz 9000 5W40 is one of those rare 5W40 that has a higher viscosity aswell. It likely has a higher HTHS as their 0W30 in the same line


Here's their 0w40 energy, which has some comparisons with other oils and grades: http://www4.total.fr/lubricants/pdf/PDS/Engine-oils/LR-Fiche-pdt-GB-Quartz-9000-Energy-0W40.pdf seems to perform better than their 5W30 in the same line which would/should/could have the thicker base oils
 
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2,339
Location
South Carolina
Does it get cold enough for the Cold Cranking Viscosity to make a difference? Or do they have a higher viscosity index and thus lower viscosity at your cold temperatures?
No but it does get down into the 20's and 30's F. The 0w and 5w oils crank much easier than the 10w's.

Edit: VI is pretty decent in the oils I use.
 
Messages
17,060
Location
Upper Midwest
When you plot those two oils in the Widman calculator how much of a viscosity deviation is there between the two winter ratings at those temperatures?
 
Messages
597
Location
Jupiter, FL
Second is that there are suddenly numerous N55 engines with rod bearings failure. But why now?
My parents 2012 X5 with the 4.4 V8 twin turbo is on its last legs and sounds like a bucket of bolts being shaken upon cold starts.. I found out their auto shop has been using 0w20/5w20 for the past few years in their engine... We live in South Florida where its quite warm. Maybe lots of owners have made the same mistake using oils much too thin for their engine.
 
Messages
169
Location
Arizona
If I had a car that called for 0w-40 or 10w-40, I'd feel comfortable switching between them depending on weather. An engine probably won't know the difference in the Southwest where I am.
 
Messages
5,379
Location
down in the park
When you plot those two oils in the Widman calculator how much of a viscosity deviation is there between the two winter ratings at those temperatures?
The widman calculator isn't accurate at those low temperatures. The oils don't follow the viscosity index anymore as curled up VII can't curl up any further and there could be wax formation in one oil vs another.

Does the widman calculator give a believable viscosity at the winter ratings? You know what the maximum is they can have
 
Messages
17,060
Location
Upper Midwest
The widman calculator isn't accurate at those low temperatures. The oils don't follow the viscosity index anymore as curled up VII can't curl up any further and there could be wax formation in one oil vs another.

Does the widman calculator give a believable viscosity at the winter ratings? You know what the maximum is they can have
He posted it was in the 20s and 30s.
 
Messages
17,060
Location
Upper Midwest
yes, which is right there where the widman calculator loses it...
All right I thought it was a bit lower than that. I remember this post by A_Harman but you're right, the temperatures are close.

 
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